Today’s announcement means testing and authentication work on the document has been completed in time for the 242nd anniversary of American Independence Day July 4, 1776.

Louise Goldsmith, leader of West Sussex County Council, said: “This is such terrific news about the Sussex Declaration. We have all been waiting to hear what the experts have been able to discover for us and now we know!

“Our Records Office holds many fascinating treasures – but this treasure of a document is very, very special indeed.

“So we very much welcome this interest in the West Sussex archives and the work of the Record Office, which acts as the custodian for thousands of documents with a West Sussex link stretching back to 780.”

ks170849-5 Chi American Declaration phot kate'Lucy Maguire in the conservation department with a copy of the original.ks170849-5 SUS-170425-162535008

Unique out of all other 18th century versions of the Declaration, the list of signatories in the Sussex Declaration are not grouped by states.

The Harvard team believe the unusual listing is reflective of the views of its most likely commissioner, James Wilson, who argued the authority of the Declaration rested on a unitary national people, and not on a federation of states.

DNA testing also revealed the parchment was prepared from sheepskin, rather than more expensive calfskin and X-ray fluorescence (XRF) capture showed high iron content in holes in the corner of the parchment, possibly iron nails to hang the parchment at some point.

West Sussex County Archivist Wendy Walker said: “We are extremely excited to hear that Harvard’s research and the scientific analyses confirms the historical significance and importance of this archive.

“It is a fascinating document and it has been fantastic for us to work with colleagues at Harvard, the Library of Congress and the British Library to find out more about the story that surrounds it.”

The discoveries are set to be published by Harvard academics Danielle Allen and Emily Sneff in their paper, “The Sussex Declaration,” in the Proceedings of the Bibliographic Society of America this autumn.

Work on the parchment was a collaboration between Allen, Sneff, researchers at the West Sussex Record Office, British Library, Library of Congress, and the University of York.

At 24” x 30.5” the parchment is on the same ornamental scale as the only other known contemporary manuscript of the Declaration of Independence on parchment, the engrossed parchment at the National Archives in Washington, D.C., which was signed by the delegates to Continental Congress.